1. Field
The present invention relates to a semiconductor design technology, and more particularly, to a signal converter for converting an input signal into a desired signal type.
2. Description of the Related Art
Semiconductor devices such as Double Data Rate Synchronous Dynamic random access memory (DDR SDRAM) convert input signals from an external source (hereafter, referred to as an input signal) into a desired signal type for use. The operation of converting the input signal is performed by a signal converter. There are different types of signal converters including Digital-to-Analog Converter (DAC), an Analog-to-Digital Converters (ADC), Time-to-Digital Converters (TDC) and the like, depending on the types of input and output signals. The DAC converts a digital input signal into an analog output signal, the ADC converts an analog input signal into a digital output signal, and the TDC converts a temporal input signal into a digital output signal. The temporal input signal inputted to the TDC has time information. Examples of the temporal input signals include a signal having a pulse width corresponding to the time information.
Recent semiconductor devices have required more rapid and precise operations. Thus, semiconductor device designers need to be sensitive to even small amounts of noise to avoid errors. When designing a signal converter, designers must consider such aspects, which generally makes their job more difficult. Hereafter, a signal converter capable of improving such concerns will be described.